Aseptic packaging is a well known method of packaging items (such as food products) when sterilization of both the item and the packaging material containing the item is required. To this end, it is known to produce a sterilized package wherein a sterile food product is placed in a sterilized container (such as a pouch) to preserve the food product for later storage or use. Various methods of sterilizing the container and filling the container with the sterilized product are known, such as (but not limited to) the use of hydrogen peroxide.
In aseptic packaging applications where hydrogen peroxide sterilization treatments are used (such as vertical or horizontal form, fill, and seal pouch packaging), some films can unduly stretch or improperly seal after pouch formation and filling with sterilized product at elevated temperatures. These films are thus less desirable or unsuitable for end use applications where dimensional stability of the packaging material is of concern.
Printed information is commonly placed on the outside surface of a package to identify the product, supplier, and the like. However, during manufacturing of the package, it is common for such surface printing to be directly exposed to a heated seal bar. As a result, the surface printing can become smeared or otherwise degraded. In addition, package surface printing is also frequently exposed to other physical abuses during distribution and display of the packaged product, causing the clarity and presentation of the printed image to be degraded. Further, when hydrogen peroxide is used during aseptic packaging, the integrity of the printed image can be compromised as a result of incompatibility with the sterilant used.
The presently disclosed film can be used for aseptic packaging applications and does not exhibit the problems with stretching or pouch formation common in the prior art. In addition, the disclosed film can be trap printed to avoid the problems experienced in the art with external printing applications.